P1084: CHECK-POINT INHIBITORS IN PATIENTS WITH RELAPSE/REFRACTORY HODGKIN’S LYMPHOMA: A RETROSPECTIVE ANALYSYS BY THE RETE EMATOLOGICA PUGLIESE (REP).
Authors: F. Gaudio, G. Loseto, V. Bozzoli, P. R. Scalzulli, A. M. Mazzone, L. Tonialini, V. Fesce, G. Quintana, G. De santis, P. Masciopinto, E. Arcuti, F. Clemente, S. Scardino, G. Tarantini, D. Pastore, L. Melillo, V. Pavone, P. Mazza, A. M. Carella, N. Cascavilla, N. Di Renzo, A. Guarini, P. Musto
Journal: HemaSphere (2022)

Background: The majority of patients with either limited stage or advanced-stage classical Hodgkin lymphoma (cHL) can be cured with chemotherapy; however, 5–10% will have refractory disease to frontline therapy and approximately 10–30% will relapse. In recent years, checkpoint/PD-1 inhibitors have significantly changed the prognosis of patients with relapsing refractory cHL, demonstrating exceptional results in heavily pretreated patients. There is limited data on the real-world experience with PD-1 inhibitors in cHL and it is unknown whether fewer selected patients treated with these agents receive benefits similar to those observed in published trials. Aims: We performed a retrospective multicentre analysis of the Rete Ematologica Pugliese (REP) of 66 patients with relapsing refractory cHL who received PD-1 inhibitors in the non-trial setting. Methods: Forty-three patients (65%) were treated with nivolumab and 23 (35%) with pembrolizumab. Median age at diagnosis was 36 years (range, 18–81) and median age at initiation of PD-1 inhibitor therapy was 43 years (range 19–86). Forty-four (67%) and 23 (35%) patients underwent autologous stem cell transplantation (SCT) and allogeneic SCT, respectively, prior to checkpoint inhibitor therapy. The median lines of treatment attempted prior to PD-1 inhibitor therapy was 4 (range, 3 to 7). All patients were treated with brentuximab vedotin prior to receiving checkpoint inhibitor therapy. Results: The best overall response rate to PD-1 inhibitor therapy was 70%: 47% complete remission (CR) and 23% partial remission (PR). Five patients (8%) achieved stable disease (SD), while 14 patients (21%) showed progressive disease (PD). In patients treated with nivolumab the response was: CR in 23 (54%), PR in 9 (21%), SD in 4 (9%), PD in 7 (16%) patients, respectively; in those treated with pembrolizumab CR occurred 8 (35%), PR in 6 (26%), SD in 1 (4%), PD in 8 (35%) patients, respectively. Twenty-four immune-related adverse events were documented (4 gastrointestinal, 4 hepatic, 6 fever, 4 hematological, 3 dermatological, 3 allergic rhinitis). Toxicity resolved in all patients and there were no deaths attributed to checkpoint inhibitor therapy. After a median follow-up of 26 months (range 3-72 months), 54 patients (82%) are alive and 12 (18%) died. The cause of death was attributed to disease progression in 9 patients, and sepsis in 3 patients. After PD-1 inhibitor therapy, 22 patients (33%) relapsed or progressed. The overall survival and progression free survival at five years were 65% and 54%, respectively. Summary/Conclusion: We demonstrate similar response rates, clinical outcome and toxicity profiles compared to clinical trials. These results support the effectiveness and tolerability of PD-1 inhibitors therapy in relapsing refractory cHL in a real-world setting.